Valve-operating system

ABSTRACT

A system including power operators for two or more main flow control valves. Devices (e.g., four-way valves) serve to control supply of energy (e.g., liquid under pressure) to the power operators, and in turn are conditioned by electrical means. In the event of failure of the electrical power supply, both of the control devices are set whereby the main valves are moved to or remain in a safe condition (e.g., closed).

United States Patent Appl. No. Filed Patented Assignee VALVE-OPERATINGSYSTEM Primary Examiner-Samuel Scott Attorney-Flehr, Hohbach, Test,Albritton & Herbert ABSTRACT: A system including power operators for twoor more main flow control valves, Devices (e.g., four-way valves) serveto control supply of energy (e.g., liquid under pressure) to the poweroperators, and in turn are conditioned by electrical means. In the eventof failure of the electrical power supply, both of the control devicesare set whereby the main valves are moved to or remain in a safecondition (e.g., closed).

2 Claims, 1 Drawing Fig.

US. Cl 137/608 Int. Cl Fl7d 1/00 Field of Search 137/608, 609, 595, 637;25 H29, 19, 20

References Cited UNITED STATES PATENTS 2,252,800 8/1941 Daniels 137/637X1 VALVE-OPERATING SYSTEM CROSS-REFERENCE TO RELATED APPLICATIONS Thisapplication is in part a continuation of subject matter disclosed andclaimed in copending application Ser. No. 719,338 filed Apr. 8, 1968,and entitled Pipeline By-Pass Flow Control System and Method." whichis'now abandoned.

BACKGROUND OF THE INVENTION In systems making use of two or more mainpower-operated valves, it is common practice to provide individualcontrol devices associated with each power operator to control itsoperation. These devices may for example be electrical reversingswitches for electrical operators, or four-way valves for operators ofthe hydraulic type. Such four-way valves may connect with sources ofliquid under pressure and they control supply and exhaust ofhydraulicliquid to the fluid chambers of the hydraulic operator. Variousarrangements can be provided for setting each such four-way controlvalve. They may be set manually or from a remote station. For programmedoperation they may be under control of a punched tape or punch card.Essential parts of such a system, such as solenoid operators or solenoidvalves, are generally energized and operated electrically. In the eventof electrical power failure, the entire system becomes inoperative, andthe main valves may be left in an unsafe condition.

SUMMARY OF THE INVENTION AND OBJECTS This invention relates generally tosystems for the operation of two or more related flow control valves,where the valves are provided with power operators.

It is an object of the invention to provide a system of the abovecharacter which, in the event of electrical power failure, will causethe main valve to assume or remain in a desired safe condition.

Another object of the invention is to provide a system of the abovecharacter which is particularly applicable where the valve operators areof the double-acting hydraulic type, together with four-way valvesconnected to the operators to control supply and exhaust of hydraulicliquid. The present invention is characterized by means whereby thecontrol valves can be operated individually, but are both acted upon inthe event of power failure to cause the power operators to condition themain valves to prevent hazards to associated equipment. Y

Another object of the invention is to provide a system of the abovecharacter which makes use of overriding pneumatic pressure forconditioning the control valves of the system in the event of a powerfailure.

The present invention makes use of two or more poweroperated main flowcontrol valves. The operators are adapted to be energized to open andclose the associated main valve. A control device is connected to eachof the valve operators for controlling the supply of energy to the same.Each control device has two operating positions, in one of which theassociated operator opens the main valve, and in the other of which thepower operator closes the associated main valve. Means are alsoassociated with each of the control valves for setting the same ineither one or the other of the two positions. In addition, a commonmeans is associated with both of the control devices for conditioningthe same to ensure that the main valves will be moved to or left in asafe condition in the event of power failure for the system.

Additional objects and features of the invention will appear from thefollowing description in which the preferred embodiment has been setforth in detail in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The single FIG. is a schematic layoutand circuit diagram illustrating the present system and method.

DESCRIPTION OF THE PREFERRED EMBODIMENT The drawing illustrates a systemincorporating two main valves 10 and 11 of the gate type, and which arepresumed to control flow of gas or liquid in an overall system. In thepetroleum industry the overall system may for example be for thegathering of liquid or gas in connection with producing wells, a pumpingstation in connection with pipe transmission lines, a tank farm for thestorage of liquid products, a custody transfer system for the handlingof products through pipe transmission lines, a metering or meter proversystem, a shipto-shore transfer system, or a system for the handling ofproducts from offshore barges or platforms. In most instances the systemwill use more than two main flow control valves. Each of the valves 10and 11 is equipped with a power operator l2 and 13. In this instance itis assumed that the power operator is of the double-acting hydraulictype, comprising a cylinder and a piston connected to the gate of themain valve. The fluid chambers of the hydraulic operators are shownconnected by piping to four-way control valves 14 and 15 which in turnare electrically controlled. With respect to valve 14, lines 17 and 18connect the valve with the hydraulic chambers of the operator 12. Alsocontrol valve 14 connects with the liquid pressure line 19 and theliquid exhaust line 21. Control valve 15 is similarly connected withoperator 13 by lines 22 and 23, and it connects with the liquid pressureline 24 and exhaust line 25.

As representative of suitable means for supplying liquid under pressure,a hydraulic pump 27 is shown having its discharge side connected to thelines 19 and 24 and its suction side connected to the reservoir 28. Thisreservoir receives liquid from the control valves 14 and 15. Motor 27 isshown being driven by the electric motor 30.

The system illustrated in the drawing also has electropneumatic meansfor operating the four-way valves 14 and 15. Thus pneumatic operators 31and 32 of the cylinder piston type have their pistons mechanicallyconnected to the operating rods of the four-way valves 14 and 15. Withrespect to pneumatic operator 31, solenoid valves 33 and 34 serve tocontrol application of pneumatic pressure from the air pressure line 35whereby the operator 31 is energized to move and set the four-way valvein either one of its two operating positions. The arrangement is suchthat when solenoid 33 is operated, air pressure is supplied to theoperated 31 in such am manner that the four-way valve is set to causethe hydraulic power operator 12 to close the associated gate valve 10.When solenoid 34 is operated, pneumatic pressure is supplied to set thefour-way valve 14 in its other position, thus causing the hydraulicoperator 12 to open the gate valve. When the solenoid valve 33 is notbeing electrically energized, it vents through the pneumatic operator 31through the line 36. When solenoid 34 is not being deenergized, it ventsthrough the line 37. In other words, when solenoid valve 33 iselectrically energized, it causes pneumatic pressure to be applied tothe upper end of pneumatic operator 31 as illustrated in the drawing.However, when the solenoid valve 33 is deenergized, pneumatic pressurevents back from operator 31 into the line 36.

Solenoid valve 34 functions in the same manner, but the vent ing is toatmosphere.

The solenoid valves 38 and 39 for the pneumatic operator 32 are likewiseconnected in the same manner to the air pressure supply line 35. Hereagain solenoid valve 38 vents through line 41 when it is deenergized,and solenoid valve 39 vents to the atmosphere through line 42. Thesolenoid valves 33 and 38 can be referred to as closing solenoids sincethey initiate closing of the associated main gate valves when thesesolenoid valves are energized. The other solenoid valves 34 and 39 canbe referred to as opening solenoids.

Electrical lines LI and L2 are representative of current supply lines ofsuitable voltage for energizing the solenoid valves. Circuits 43 and 44connect between lines L1 and L2 and the windings of the solenoid valves33 and 34 and are provided with control switches 46 and 47. Similarcircuits 48 and .49 connect with the windings of solenoid valves 38 and39 and are providedwith switches 51 and 52.

Alternating current lines L3 and L4 represent a higher voltage powersource. Motor 30 is shown connected to these lines by circuit 53 throughthe starting box 54. It is assumed that lines L1 and L2 together withlines L3 and L4 actually represent a common power source. In otherwords, a stepdown transformer 55 and rectifier 56 connect with lines L3and L4 to supply direct current at a suitable lower voltage to the linesL1 and L2.

Both of the pneumatic exhaust lines 36 and 4] connect to a commonpneumatic reservoir 57. A solenoid valve 58 connects to a source ofpneumatic pressure through line 59 and also with reservoir 56 throughline 59. When this valve is energized, line 60 is vented to theatmosphere through line 61. However, when the solenoid valve 58 isdeenergized, line 60 is placed in communication with the air supply line59 whereby a substantial pressure is applied to the reservoir 56.

The windings of solenoid valve 58 connect with a circuit 62 whichincludes the current supply lines L1 and L2 and a voltage-sensing device63. This sensing device also connects across the lines L3 and L4 and isset or adjusted whereby when the voltage across lines L3 and L4 fallsbelow a predetermined normal value, contacts in device 63 are opened toopen the circuit 62 and thus deenergize the windings of solenoid valve58. As pointed out above, this serves to pressurize the reservoir 57.

Operation of the system and method is as follows. It is assumed that theswitches 46 and 47 for valve and the switches 51 and 52 for valve 11 areoperated either manually or through some control device, such as aperforated tape, perforated card or the like, to cause the opening andclosing of the valves 10 and 11 as desired. Also it is assumed that onedesires to be certain that the valves 10 and 11 are in closed position,or moved to closed position, in the event of power failure. Normallywhen the power is normal, or in other words, when the voltage is withinnormal limits across lines L3 and L4, the solenoid valve 57 remainsenergized, and therefore the reservoir 56 is at atmospheric pressure.Under such conditions, selective operation of switches 46 and 47 forvalve 10 serves to energize and deenergize the solenoid valves 33 and 34which in turn energizes the pneumatic operator 3] to condition thefour-way valve 14 to cause hydraulic liquid to be supplied to theoperator 12 to close or open the main valve. The same applies tooperation of switches 51 and 52 for the valve 11. In the event of anelectrical power failure, one or both of the main valves may be in openposition. Also one or both of the main valves may be 'in the process ofmoving to open position. When a power failure does occur, the winding ofsolenoid 58 is deenergized as previously described, and this causes thereservoir 57 to be pressurized. This serves to apply overriding pressurethrough both of the lines 36 and 41, thereby making certain that thefour-way valves 14 and 15 are positioned to cause operation of thehydraulic operators l2 and 13 to close a valve if it is open or inpartially open position.

It will be evident from the foregoing that the present system and methodmakes possible a factor of safety in the operation of power operatedvalves. It does not interfere with the individual power operation ofeach valve, but it does ensure that valves are left in closed positionin the event of a power failure.

In some instances it may be desirable to have the gate valves in openposition after a power failure. In such event changes can be made toensure that the overriding pneumatic pressure is applied through theopening solenoid valves rather than the closing valves.

We claim:

1. In a system for the power opening and closing of at least two mainvalves, a power operator of the hydraulic type connected to each of saidvalves and adapted to be energized by a lication of hydraulic liquid tooperate the same, control PF va ves of the four-way type connected toeach of said operators and movable between two operating positions forcontrolling application and discharge of liquid from the same,

electro pneumatic means associated with each of said fourway valves forsetting the same, each of said means including a pneumatic operatormechanically connected to the associated four-way valve and two solenoidvalves connected to control supply of pneumatic pressure to saidpneumatic operator, said pneumatic operator exerting force to move theassociated four-way valve from one operating position to the other,electrically energizing one of said solenoid valves serving to energizethe pneumatic operator to move the associated four-way valve to causethe main valve to be closed, and electrically energizing the othersolenoid valve serving to supply pneumatic pressure to the pneumaticoperator to move the associated four-way valve to cause the poweroperator to open the valve, an electrical operating circuit connected toeach of said solenoid valves, each circuit including a source ofelectrical power and a switch adapted to be closed or opened toselectively operate the associated solenoid valve, a vent line connectedto each of said first one of said two solenoid valves, the other one ofsaid solenoid valves being arranged to vent to the atmosphere, and meansresponsive to a failure of the electrical power connected to saidcircuits for supplying pneumatic pressure to both of said vent lines toprovide overriding pneumatic pressure to said pneumatic operators,thereby ensuring that the four-way valves will be positioned to maintainthe valves closed or to close the same.

2. A system as in claim 1 in which said last means consists of apneumatic pressure reservoir, both of said vent lines being connected tosaid reservoir, and valve means for venting said pneumatic reservoir toatmosphere or to pressurize the same, said last means being responsiveto an abnormal drop in electrical power supply voltage.

1. In a system for the power opening and closing of at least two mainvalves, a power operator of the hydraulic type connected to each of saidvalves and adapted to be energized by application of hydraulic liquid tooperate the same, control valves of the fourway type connected to eachof said operators and movable between two operating positions forcontrolling application and discharge of liquid from the same, electropneumatic means associated with each of said four-way valves for settingthe same, each of said means including a pneumatic operator mechanicallyconnected to the associated four-way valve and two solenoid valvesconnected to control supply of pneumatic pressure to said pneumaticoperator, said pneumatic operator exerting force to move the associatedfour-way valve from one operating position to the other, electricallyenergizing one of said solenoid valves serving to energize the pneumaticoperator to move the associated four-way valve to cause the main valveto be closed, and electrically energizing the other solenoid valveserving to supply pneumatic pressure to the pneumatic operator to movethe associated four-way valve to cause the power operator to open thevalve, an electrical operating circuit connected to each of saidsolenoid valves, each circuit including a source of electrical power anda switch adapted to be closed or opened to selectively operate theassociated solenoid valve, a vent line connected to each of said firstone of said two solenoid valves, the other one of said solenoid valvesbeing arranged to vent to the atmosphere, and means responsive to afailure of the electrical power connected to said circuits for supplyingpneumatic pressure to both of said vent lines to provide overridingpneumatic pressure to said pneumatic operators, thereby ensuring thatthe four-way valves will be positioned to maintain the valves closed orto close the same.
 2. A system as in claim 1 in which said last meansconsists of a pneumatic pressure reservoir, both of said vent linesbeing connected to said reservoir, and valve means for venting saidpneumatic reservoir to atmosphere or to pressurize the same, said lastmeans being responsive to an abnormal drop in electrical power supplyvoltage.